I. Field of the Invention
This invention relates to a new system of achieving vertical lift for an aircraft or other vehicle or machine. More particularly, the invention relates to a device incorporating such a system.
II. Brief Description of the Prior Art
This invention makes use of the effect described by Magnus (1854) according to which a rapidly rotating cylinder immersed within a fluid flux or moving stream will generate a vector perpendicular to this stream. To be more precise, a low pressure zone (depression) appears on the surface of the rotating cylinder and this depression reaches its maximum value where the surface of the cylinder is moving in approximately the same direction as the stream. The lift vector produced in this way is approximately perpendicular to the stream, and directed away from the surface of the cylinder.
Several inventions have been made in which a rotating cylinder is integrated into the leading edge or in the extrados of a classical wing. These inventions are generally aimed only at increasing the lift in standard flight and are not related in any way with the vertical flight which is the purpose of the present invention.
In 1942, Parlee C. Grose invented an aircraft capable of generating vertical lift (U.S. Pat. No. 2,417,358). In this patent, in accordance with the classical description of the Magnus effect, lift is generated by rotating cylinders immersed in a pumped air stream. The cylinders are arranged in symmetrically opposed pairs and are always parallel to the fuselage of the aircraft. The air stream generating the lift is pumped directly onto the cylinders by a motorized blowing system, so the lift is independent of the forward movement of the aircraft. Such an aircraft is consequently able to fly without moving forward or, in other terms, to fly vertically. An aircraft such as proposed by Grose can also be equipped with classical wings which permit standard flight when sufficient forward speed is attained. It seems that this invention was never actually realized.
In 1970, F. T. Elliott was awarded U.S. Pat. No. 3,630,470 for an aircraft using Magnus cylinders. An analysis of this invention shows a turbine/blower located on the top of the aircraft, this blower projecting a stream of air downwardly through a large duct located in the center of the aircraft. This main duct is then subdivided into secondary ducts which in turn meet 90-degree elbows that reorient the secondary air streams horizontally and radially from the center of the aircraft. The Magnus cylinders are installed in these elbows, immersed in the middle of the secondary ducts. Again, it seems that no practical use of this invention was ever made, perhaps because the aforementioned elbows cause a concentration of the moving fluid directly "under" the rotating cylinders, which is exactly the opposite of what must be achieved to obtain maximum useful lift.
In 1963, J. Barnes was awarded U.S. Pat. No. 3,071,334 for a vertical lift aircraft. In an arrangement which bears some resemblance with the above mentioned patent to Elliott, Barnes has designed an aircraft with, right in its center, a large vertical turbine directed downward and then with a baffle which divides and redirects the air flux 90 degrees horizontally in two opposed directions toward the lower lifting structures. These lower lifting structures are either static, curved surfaces like wing extrados or some (Magnus type) rotating cylinders. Unlike Elliott, Barnes states (Column 2, lines 31-36) that a baffle causes the downwardly moving air to move laterally and then over the rotating cylinders. Beside this brief statement, however, there is no other description of this important characteristic. The drawings show that the downwardly moving air is directed against a perfectly flat plate in alignment with the very axis of the rotating cylinders, henceforth this flat plate is perpendicular to the surface of the cylinder at the point they come close to each other. The drawings show a more or less wide gap between the tip of this plate and the surface of the cylinder; there is no indication on how to prevent a portion of the air flow (which arrives to the cylinder with a right angle) from flowing under the cylinder through that gap. The fact that the flux of air hits the cylinder with a right angle, the presence of a gap at the tip of the baffle and the absence of any streamlining in the Barnes device maintains a zone of pressure on the windward side of the cylinder and generates turbulences. This negatively affects the lift coefficient. On the lee side of the cylinder, the absence of any device to remove the air stream away from the surface of the cylinder together with the Coanda effect causes the air stream to stick to the cylinder and go around it. This extends the zone of depression farther around the cylinder, to the detriment of the practical and useful vertical lift generated on the top of the cylinder.
Barnes proposes to control such an aircraft with flaps located right above the lower rotating cylinders, about one radius away from the surface of the cylinders. From the drawings, we see that the leading edge of such flaps are located about 20/30 degrees downstream after a vertical line crossing the axis of the cylinder. Such movable flaps actually channel the air stream between their under surfaces (intrados) and the surface of the cylinders. This is equivalent to directing the flow into a pipe, with a very imperfect contact with the atmosphere, and henceforth without useful depression and lift.
Furthermore, the two lower bow cylinders are bluntly facing the front of the aircraft. As soon as the aircraft moves ahead, the wind generated by this movement would go right against the pumped flow crossing these rotating cylinders, diminishing or cancelling any lift there might be there and thus causing the aircraft to tumble down.
Barnes also has designed some rotating cylinders located on the top of the aircraft (identified by reference numerals 19 and 21 in FIG. 2), just beside the inlet of the vertical turbine and duct. It is said that the air attracted by the turbine will flow first over these rotating cylinders. Unfortunately, experimental evidence show that the air being drawn into a pump cannot be "directed". This drawing of air into a pump or a turbine causes a stream with a form of a fan which is converging from all directions toward the inlet port; this stream has always a very short extension and the speed of this stream is decreasing almost exponentially as the distance from the inlet port is increasing. No practical realization of the Barnes invention is known.
An object of the present invention is to make use of the Magnus effect in an effective and practical way for providing lift in an aircraft, other vehicle or machine.
Another object is to provide a device which maximizes the lift available from Magnus cylinders, thus making the effect of the cylinders more practically useful.
Yet another object of the invention is to overcome some or all of the problems of the prior devices when attempting to make use of lift generated by Magnus cylinders.